Clark has played 49 consecutive Warriors matches at lock, after one appearance from the bench last season.
The 29-year-old will start at No.13 against Newcastle in Sunday's elimination final at Eden Park.
Clinton Toopi told AAP: "When he was at the Titans I think Erin lost his identity in terms of who he is," after five unsettled Gold Coast seasons.
Across 50 Warriors games, Auckland-born Clark has averaged 135m, compared with 65m during his Titans career.
His 2686 post-contact metres in Auckland exceed the 2113m recorded across 94 matches for Gold Coast.
Clark began in the Warriors system, played NSW Cup in the halves, then moved to the Titans after one NRL match.
His attack includes short balls, offloads, flick passes and grubbers alongside powerful running and aggressive defence.
Toopi recalled losing the 2002 decider to the Sydney Roosters before 90,000 spectators: "These Warriors boys will want to walk off the field having no regrets at all."